Five Cylinder Engine
pricing and purchasing

HCI Aviation is a small company with a simple goal: to provide homebuilders an alternative to the high-revving two stroke engines or engines that were designed for cars.

Radial engines are much lighter than inline and flat opposed engines of similar displacements.

Our design process began with a study of small engine history. Liston provided the numbers, while Gunston and Smith furnished the history. Sam Heron was our philosopher. Designing a radial to match the performance of the classics is not difficult when the engineer has access to modern alloys and gasoline. With the newer materials it is practical to double the compression ratio used by Kinner, LeBlond, Viele,...etc. With this higher thermal efficiency, the natural weight advantage of the radial yields an engine with competitive power to weight ratio.

R-180 movie